This weekend's Oktoberfest was a showcase for the changes at the Ann Arbor institution. "We have a really loyal base of people who like what they like," general manager Stacy Baird said. "So we wanted tradition and innovation to meet."

That meant updating the menu without replacing old favorites. From a beet, kale and goat cheese pizza to a a trio of new burgers from pork belly to Hawaiian-style, they tried to keep it simple while putting good tastes together, Baird said. The popular mac and cheese amps up the truffle oil and adds white cheddar for tang. The completely revamped dessert menu includes a chocolate stout cake with candied barley.

"We basically made an Irish car bomb into a cake," Baird said.

Inside the brewpub, there's new lighting and a new glass door that gives dining patrons a look at the brewing process.

And then there's the beer. Head brewer Duncan Williams said that after two decades, Grizzly Peak maintains its English-driven brewing philosophy but experiments with new and emerging styles. This weekend, the brewpub celebrated its anniversary with an Oktoberfest celebration, and featured both a fest beer -- a version of a traditional German Oktoberfest beer, with more emphasis on hops and less on the traditional malty flavor -- and an anniversary brew, Grizzly Peak XX Pale Ale, a riff on the brewpub's standard pale ale with more hops and malt.

"It's bigger malt, bigger Cascade hops, bigger alcohol," Williams said about the anniversary brew, which clocks in at 7.5% ABV (compared to the usual pale ale at 5.2%).

It's hoppy, yet smooth.Williams brought in a team of past Grizzly Peak brewers to collaborate on the anniversary ale, inlcuding Ron Jeffries of Jolly Pumpkin, Stacy Roth, head brewer at Griffin Claw, Sean Brennan of Original Gravity and Nathan Hukill from Bitter Old Fecker Rustic Ales. These brewers, as well as many others, have spent time at a number of Michigan brewpubs. Their resumes seem to overlap quite a bit.

Williams also experimented with a summer series of "table beers," relatively low-alcohol yet highly flavorful brews. One of those beers, Table Dance, was a collaboration with the Grand Rapids-based female brewing collective Fermenta. Williams said he resists the "obsession with super-hoppy IPAs because good stuff like kolsch and lagers get lost."

Still, you can find Belgians and saisons on the Grizzly Peak menu. Look for the Michigan saisoniere, featuring Michigan malts and hops, in the next week or so.

Around Halloween, Williams expects to tap into a Klebenkop, an autumn beer brewed both with candy corn and pumpkin, with a little spice thrown into the mix. Not too much spice, because Williams says too often with pumpkin beers the pumpkin gets lost.

Grizzly Peak uses a 14-barrel steam-powered brewing system, which has the flexibility to brew smaller 7-barrel batches.Last year, Grizzly Peak brewed around 1,650 barrels. "For a number of years, we made the most barrels in a year of any brewpub in Michigan," Williams said, although recently that accolade has gone to Rochester Mills Brewing Co.

Williams lauds the strong craft beer scene in Michigan.

"Years ago, you could just open a brrewpub and people would drink the beer because it was made here," he said. "Now there's competition and a focus on quality that will carry us through."